Electrical connector having resilient inserts



Aug. 7, 1951 l.1. R. FREI ET AL ELECTRICAL CONNECTOR HAVING RESILIENTINSERTS Filed Aug. 18, 1945 .\M.. /Iti//////// ATTORNEY.

Patented Aug. 7, 1951 ELECTRICAL CONNECTOR HAVING BESILIENT INSEBTSJakob B. Frei and William A. Uline, Sidney, N. Y., assignors to BendixAviation Corporation, New York, N. Y., a corporation of DelawareApplication August 1,8, 1945, Serial No. 811.372

This invention relates to electrical connectors. and particularly tomeans of the plug and `iack or pin contact and socket contact type forconnecting electrical conductors.

It is an object of the invention to make a connection that willmechanically and electrically shield a pin and socket so that vibrationwill not jar the connection loose or destroy the electric shielding.

Another object of the invention is to mount a pin and socket inresilient mountings under compression in order to support and protectthe con nection between them.

Another object is to mount a pin and socket in shells or casings so thatthe casings may interchangeably mounteither the pin or the socket.

Another object is to assemble a plurality of pins in a novel mountA sothat they will be freely self-aligning with similarly mounted sockets.

Another object is to prepare pin and socket contacts having resistanceapproaching that of copper wire and having surface contact producing aminimum amount of heat on the passage of a current.

Another object is to prepare spring sockets that retain their resilienceat temperatures harmful to the resilience of prior art sockets, and thatare capable of retaining their resilience at temperatures materiallyhigher than that employed in' preparing them.

A further object is to make a novel socket having spring fingers adaptedto make contact with broad surfaces of a pin along substantial lengthsof the telescoped parts.

A further object is to mount pins and sockets removably in connectiblemetal shells in inserts of resilient type adapted to align, support,protect, and seal the connection and all its parts.

A still further object is to employ a resilient mount for pin and socketconnections that permits natural iloating of the pin and socket duringthe making of the connection.

The above and furtherobjects and novel fea-v tures of the invention willmore fully appear from the following detailed description when the sameis read in connection with the accompanying drawings. It is to beexpressly understood, however, that the drawings are for the purpose ofillustration only, and are'not intended as a definition of the limits ofthe invention, reference for this latter purpose being had primarily tothe appended claims.

In the drawings, wherein like reference characters refer to like partsthroughout -the several views,

8 Chim.. (Cl. 173-828) Fig. l is a longitudinal section through thesocket shell showing the socket and socket inserts in place, taken onthe line I--i of Fig. 2;

Fig. 2 is an end view of the embodiment shown in Fig. 1 showing the endsof six sockets mounted in the socket insert;

Fig. 3 is a longitudinal section through the pin shell showing the pinsand pin insert in place, taken on the line l-l of Fig. 4;

Fig. 4 is an end view of the device of Fig. 3 showing the contact pinsmounted in the insert;

Fig. 5 is an enlarged plan view, partly in section and with parts brokenaway, of a preferred form of socket;

Fig. 6 is a greatly enlarged end view of the socket shown in Fig. 5,showing the ends of the contact fingers or prongs; and

Fig. 7 is an enlarged view, partly in section and with parts brokenaway, illustrating one form of pin that may be employed.

The invention embodies, among other features, a novel pin and socketthat have superior characteristics, particularly for use underconditions that subject the connection to abuse, to strains,particularly those that tend to break the connection at the joint, andto destructive forces such as heat, blows, or intense vibration. Thatpin and socket connection is claimed in a cepending application illed ofeven date herewith, but its properties and construction form a part ofthe combination of this invention and will be described here. One formof the novel pins and sockets is found in Figs. 1 and 3. In thesefigures Il represents a socket and particularly the body portionthereof. This socket is preferably an integral structure having a well,abutments, and contact fingers. It may be made of any satisfactory,electrically conductive material but is preferably made of berylliumcopper, silver plated on contact surfaces. The metallurgicalconstitution of this socket is novel in itself, and the constitution ofthe socket in combination with the constitution of the pin is alsonovel. At one end of the socket a solder well is provided, the nature ofwhich can best be comprehended from a consideration of the well Il ofFig. 5. which is identical with the construction employed in the pin andsocket of Figs. 1 and 3. The well consists of a hole Il drilled orotherwise formed in the end I2 of the socket and having a portion of oneside wall removed from points Il at the end of the socket to a point I4on the side thereof. The opening in the side of the well gives access tothe well so that the end I5 of a wire may be inserted and soldered inplace without difficulty.

mesma The bottom of the well is conical in shape as shown at I8 in orderthat the wire may be centered in the well before soldering. The wellextends below the point |4 so that vthe solder has circumferentialattachment to the wall of the well. By this means a positive andpermanent connection between the velectric wire and the pin or socket isassured. In large elements, the cut side may be omitted from the well.

Novel abutments are provided on the pins and sockets to provide forresiliently mounting them in the resilient inserts that constitutefurther although it is preferred to make them mountable,

or dismountable.

The abutments on the socket shown in Fig. 5 will be described asrepresentative. In Figure 5 the body` portion l0' of the socket isprovided with abutments 2U and 2| which are annular and havey planesurfaces 22, 23 facing each other. The abutment 2U has a conical surface24 toward the well end of the socket. The surface of the abutment 2| iscontinued cylindrlcally toward the fingered end of the socket, thefingers of which constitute in effect a conical surface adapted to aidin mounting the socket in the novel rubber inserts. i s

Referring more particularly to Figs. 1 and 2, the contact elements orfingers of the socket l are preferably integral with the socket. Onemethod of manufacturing a socket with such fingers consists in cuttingan annular groove in the body I0' of a beryllium-copper rod, turningdown the end I2 of the rod cylindrically, and the end 30' conically. Theend of the rod is drilled to a depth indicated by the dotted lines 25 inFig. 5 to a diameter slightly larger than the pin, .001 to .003clearance being satisfactory. The bored end of the rod is then milled toprovide longitudinally extending slots 26, 21 (Fig. 6) extending toadepth preferably, but not necessarily, somewhat less than the depth ofthe central bore, as indicated at 26' in Fig. 5. 'I'he bore is thenburnished to remove burrs. There are thus provided 2, 3, 4- or morefingers each of which has cylindrical inner and outer surfaces joined bydat sides. The fingers soformed are now bent toward each other by a toolthat engages them near the base so that they assume theA relation shownin Figs. 1, 2, and 6, and are fixed in that position. This formation canbe made by applying cold bending pressures to the fingers near the endsof the slots with a subsequent heat treatment at about 575 F. Thesockets so formed as shown in Figs. 5 and 1 have four fingers 30, 3|, 32and 33 which inherently possess spring properties and are capable ofgripping a pin so that material forces may be required to withdraw itfrom its socket. from about one half to two pounds being required with a#16 contact andl to 20 pounds with a #0 contact. The construction of thefingers and their conformation may be varied to vary the degree of forceneeded to withdraw the plug, so that either greater or lesser forcesthan those stated maybe required. By appropriate methods of formation agreater or lesser number of fingers may be provided. v

In very small sockets the fingers may have little or no taper, but inother sizes it is preferred that they be tapered in order that thefingers may curve to conform to the pin throughout their overlappedareas. In the form shown in Fig. 5, the ngers 30', 3|', 32', and 33 aretapered from the base toward the point, thus providing flexibility thatincreases from their bases to their points, so that upon insertion ofthe jack, the exing of the fingers begins at the point and proceedsupwardly along the fingers as the point of the pin is advanced. Whenemplaced, the pin is preferably not inserted to the base of the socketbut only part way, so that the set of the ngers is not destroyed attheir bases. Thistapered form has great advantages in securing contactand equal gripping interaction between all portions of the overlappedtelescoped body of the socket. This modified form of socket as soconstituted is a major improvement over other forms of sockets.

The novel pins, adapted for cooperation with the sockets that have justbeen described, are preferably made of tellurium copper, silver platedon each 'contact face, and comprise a body portion 40 (Figs. 3 and 7)having at one end a well similar to that which has been described and'at the other end va cylindrical pin or prong 4| having a rounded end 42adapted to cooperate with the internal bevels 34 in the ends of thesocket fingers to spring the said fingers apart in seating the pin. Themain portions of the pin have abutments 20' which are identical withabutments 20 of the sockets in size and conformation, and abutments 2|'which differ from abutments 2| only in being reduced by a conical face43 at the end of the pin 4|. The distance between the facing planarsurfaces 22', 23 of the abutments 20'vand 2|' is equal to the distancebetween the facing planar surfaces of abutments 20 and 2| so that thesockets and pins are interchangeable in their resilient inserts.

A novel feature of this invention consists in mounting the novel pin andsocket resiliently within protective shells but so that the resilienceof the mounting can be availed of to improve creepage and flashoverconditions. In addition to this broad and general inventive concept thisnovel mounting means embodies a number of new and useful conceptions andimprovements the nature of which will be set forth or will be deduciblefrom the structure as the description proceeds. l

Mounting means comprises an insert 50 of rubber or like resilientmaterial is provided for the sockets I0. This insert is provided withholes 5| which extend from end to end thereof but Awhich are reduced ata place 52 within the insert or block to provide a'plurality of annularshoulders 53, 54 adapted for seating between abutments 20 and 2| of thesocket. rl'he holes 5| may be of size equal to the size of the abutmentsor somewhat smaller, a slightly lesser diameter being preferred in orderto insure the firm contact of the rubber insert 50 with the body and theabutments of the socket. Inasmuch as the abutments 2U and 2| and 20',2|' are equally spaced, either the pin or the socket may be mounted inthe insert 50. The insert 55 preferably extends beyond the points of thesocket fingers as shown in Fig. l, or beyond'the end of the pin, therelative extent of inserts 50 and 55 being selectible to adapt thestructure to particular circumstances.

An insert 55 of resilient mounting material, such as natural rubber orsynthetic rubber, serves to mount the pins 4B, being provided with holeshaving reduced portions 52' substantially equal in extent to the reducedportions 52 of the space between the abutments. Insert block 55 is shownin Fig. 3 as of less length than `the insert block 50 and having aspherical face i adapted to make contact with the planar face 51 on theblock 50, and by reason of its spherical form to squeeze moisture andair out of the connection. The pins and sockets may be molded into theinserts if desired. One of the inserts may be made of flexible and theother of comparatively rigid material consistent with the requirementsof insertion in the shells and reception of the pin or socket. Y

The resilient inserts ae of columnar type and are compressively engagedwith the metal shell for a substantial part of their length, asindicated in Fig. l, engaging land 59', groove 52,` and the land at 80,but the remainder of the insert is circumferentially spaced from theshell as shown between numbers 51 and 16 in Fig. l and Fig. 2. Thisspace permits the rubber, which is incompressible, to flow so that theengaged faces of the inserts 50-55 can aecommodate each other and form aperfect seal. As the shells are drawn together the rubber fills thespace so` that as the end 99 seats upon the ring 81 the contacts arefirmly but resiliently supported in every direction.

The land formed at the middle of the shell constitutes a constrictionthrough which the entire land 58 has to be forced to dismantle theparts. This can only be done by slow pressure, as a sudden thrustdefeats its purpose. The land cannot be folded over, and must be causedto flow progressively through the constriction.

The well ends of the pins and sockets are seated in substantiallyidentical grommets or protective sleeves 60, 60', the description of oneof which will sufce. These sleeves, and inserts 50, 55 are made ofrubber or synthetic rubber or some other resilient dielectric materialhaving holes 6l extending from end to end thereof and through conicalbosses E2 and cylindrical bosses 53. The holes 6i are preferably thesize of the wire and less than the diameter of the well end of the pins,or sockets, so that firm and protective contact will be offeredthroughout the telescoped lengths thereof and particularly at thesoldered connection to prevent vibrations from breaking thecomparatively inflexible soldered joint. The conical bosses areadaptedto be seated in the ends of the holes 5| in the inserts 50. 55and to make firm and sealing contact with the edges thereof. The sleeves60 and 60 have annular flanges 64 and 6I of equal size which may bebevelled at the leading edge for seating purposes if desired.

The outer surface of the insert 50 is provided with an annular raisedland 58 which has a planar abutting face 59 at one end and a conicalface 59 adapted to aid in mounting in the shells. at the other end. Thelands are of equal size in inserts 50 and 55 and are equally spaced fromone end of the insert in order to adapt the inserts to interchangeablemounting in the protective shells to be hereinafter described.

It is desired to give the structure heretofore described mechanicalprotection against separation and damage -and also electricalprotection, in order that electrical ernanations from other sources maynot affect the connection and so that electrical emanations from theconnections may not aifect other electrical instrumentalities. In orderto accomplish this, novel protective and r 6 shielding means areprovided and now will be described.

As shown in Fig. 1 the sockets are enclosed in a four-part metallicsocket shell possessing a number of novel features. The shell may bemade of aluminum or other metals, or if electrical shielding is not ofthe essence, of strong inert material such as phenol-formaldehyde resinor other `strong organic materials capable of forming to the desiredshape. The shielded conduit 10 which carries the insulated wires l5inside it has its end received `within a ferrule or collar 1| forming apart of the protective shell and lnternally provided with a shoulder 12upon which the end of theconduit is adapted to rest. The other end ofthe ferrule 1| is provided with an annular flange 13 having aspherically bevelled surface 1l adaptedto be seated within a conicalsurface 15 of a sleeve 16 that forms the basic protecting and aligningmember of the socket shell. The abutting faces of the ferr-ule 1I andthe sleeve I6 are held in contact by a screw threaded clamping ring 11which is mounted on the member 16 and overlaps flange 13, as shown inFig. 1. By tightening the clamping ring 11 upon the flange 13 aspherical surface of the flange is brought into electrically andmechanically sealing relation to the end of member 16, thereby providingline contact and an excellent radioshielding joint.

The sleeve 16 is internally provided with annular abutments 18, 19,adapted to seat the land 58 and the flange 54 of the insert 50 andsleeve 60, and is externally provided with an annular flange designed toafford a purchase for the clamping ring 86, and with a sphericallybevelled surface B1 similar to surface 14. The sleeve 15 is alsoprovided with a slot 89 which guides the mechanic in aligning ororienting the insert 50 and its assembled contacts within the shell, andaligns the cooperating member 96 of the shell to insure desiredconnections between the various pins and sockets.

The mounting for the sockets, as above described, is constructed forcooperation with a mounting for the pins. This latter mounting is shownin Fig. 3 and comprises a single metallic sleeve having an annularflange 9| for mounting the connection upon a support, as by means ofholes 92 (Fig. 4), and being internally provided with annular abutments83, 94, 95 for the inserting of sleeve 60' and insert 55. Abutments 93and 95 may be provided with bevelled outside edges. as shown, to assistin inserting the inserts. The sleeve projects at 96 beyond the pins Ilfor cooperation with clamping -ring BB and is internally provided with alug 98 for cooperation with the slot 89 in the sleeve 85. The end of the`sleeve projection 96 is internally conically bevelled at 99 for linecontact against. the spherical surface 81 of the flangev85.

In one method of assembling the connection which has thus beendescribed, the insulated wires l5' are pulled through the cable member'In'. if.one is used at this end of the connector. the ends of the wiresare cleaned, as will be understood by electricians, and drawn throughthe holes in the sleeve member GU', and through the sleeve 90. The endsof the wires are then seated in the wells at the ends of the pins andsoldered in place before insertion of the pins into inserts 55. The pinsare then forced into position in insert 55 with the aid of the bevels 43of the abutments 2l'. The insert carrying the emplaced plugs is nowforced into the sleeve 90 past cooperating bevels as shown in Fig. 3.Any alternative and satisfactory method of assembly may be used, forinstance. to put the insert in the sleeve and force the pins into place.The sleeve 60' is then inserted between the abutments 93 and 94 pastcooperating bevels, and the conduit 10' is brought into abutting oroverlapping relationship with the boss 63' or sleeve 90. In seating theinsert the pins must be brought into a definite relation to the lug 98,two of the pins in Fig. 4 being shown as in diametrical alignment withthe said lug. This alignment should preferably be within 30 minutes ofarc and may be accomplished by any of many suitable known methods, suchas by reference marks or interfitting tongues and grooves on inserts 55,and shell member 90. In assembled relation the adjacent facesof insert55 and sleeve 60' are in rm engagement and the conical bosses 62 tsnugly into the holes through block 55.

In a. similar manner, the wires I5 are drawn out of the conduit andthrough the cooperating shell members, and through the sleeve beforebeing secured in the solder wells of the sockets l0. The sockets arethen inserted in theinsert 50 until the land 52 is seated between theabutments 2u and 2l. If desired. of course, the sockets may be mountedin insert 50 by forcing the latter over the conically shaped pronged endof the socket. The sleeve 16 is then mounted upon the insert assemblywith the aid of cooperating flanges 19, 8U and the sleeve 60 is emplacedin a manner similar to the emplacement of sleeve 60'.' The ferrule 1l isthen mounted on thefend of the sleeve by connecting ring 11. The insert50 must be mounted in proper angular alignment or orientation with theslot 89 in a pre-determined relation and preferably within 30 minutes ofarc as described for the pins in relation to the lug 98. Thecorresponding openings inthe inserts may be lettered or numberedfor theconvenience of the electrician. -As in the plug portion of the joint,`the adjacent faces of insert 50 and sleeve block 6l) are in iirmengagement when said blocks assume the illustrated positions in shellmember 16 and bosses 62 are squeezed into openings 5l. Also, thesurfaces 14, are brought into rm engagement to provide a moisture tightseal and a good radioA shielding joint.

In making the connection between sockets and pins the lug 98 is alignedwith the slot 89 and the sleeves 16 and 96 are telescoped, bringing thepins 42 in alignment with the sockets. The pins and sockets can now betelescoped, and the connection made substantially permanent, by rotatingthe ring 86 until the faces 51 and 56 of the inserts 50 and 55 abut. Byapplying further pressure through the ring 86, the blocks 50 and 55 canbe put under compression in order to increase the firmness with whichthe plugs and jacks are held and to provide a tight joint to eliminatemoisture and perfect the sealing. If lubricant is used to aid in seatingthe blocks, it should be of dielectric type and be kept off the solderwell. f

An advantage of thisl invention is the provision of strong andwellprotected connections between electrical line terminals andshielding conduits -therefor in which the protection is both mechanicaland electrical. Another advantage is the Aprovision of resilientmountings for electrical. A connections, the resilience of which can bealtered to suit the circumstances of use. An-

other advantage of the invention is the provision of a mounting which ismore lasting under conditions of severe vibration. Another advantage isa superior electrical connection by jacks and plugs in which contact ismaintained substantially throughout the telescoped lengths thereof.Another advantage is in the superior metallurgical construction of theparts. Additionally. the connection provided is waterproof and insuresagainst electrical and magnetic emanations which interfere with radioreception. The novel construction provided also provides substantialassurance against flashovers between adjacent conductors. Yet anotheradvantage of the invention arises from the overlapping and interttlng ofthe sleeves 16 and 96, which prevent the bending and breaking of theconnection at the joint.

Other advantages will be apparent to persons skilled in the art.

Although only one embodiment of the present invention is hereinillustrated and described, it is to be expressly understood that thesame is not limited thereto. Various changes may be made therein,particularly in the design and arrangement of the parts illustratedwithout departing from the spirit` and scope of the invention, as willnow be apparent to those skilled in the art.

What is claimed is: f

1. An electrical connector including two rigid, annular metal shellshaving snugly intertting ends and circular opposed surfaces providinginternal metal to metal electrical shielding in assembled relation,aligning means having a part on each shell for aligning the shells,means to hold the said ends together in interntting relationship,resilient dielectric inserts compressively iitted to the inside of eachsaid shell and having opposed faces adapted to make sealing contact witheach other, said inserts having holes for the reception of electricalconnectors, plug and socket electrical connectors compressively andcooperatively mounted in the said holes, said connectors in each saidinsert being aligned with the respective parts of said aligning means, acooperating circumferential land and groove formed in the bodies of eachsaid shell and its insert, at least one of said inserts beingcircumferentially spaced from its shell adjacent to its said opposedface, and a cooperating circumferential land and groove formed in thebodies of each insert and its compressively held connectors, the insertsin said shells meeting and being subject to compression against eachother when the shells are joined by said holding means. I

2. An electrical connection comprising connectible shells havingone-piece, telescoping cylinders with elemental aligning means, meanswithin and integral with each said shell receiving and retaining aresilient mounting insert,

. eccentrically positioned means within each said mounting insertreceiving and retaining one member of a pin and socket connection,cooperating elemental aligning means in the inserts and shells, saidmounting inserts being of such size and construction that abutting facesthereof may be held under sealing compression about said members whensaid pin and socket are electrically connected, and at least one of saidinserts being circumferentially spaced from its shell, adjacent to itssaid abutting face.

3. 'An electrical connector including cooperating contacts of pin andsocket type, resilient dielectric inserts having hcles in which saidcontacts are mounted and having opposed faces adapted to make sealingcontact about said contacts, said inserts and contacts havingcompressively interi'ltting lands and grooves cooperating to yieldablyhold the contacts in the inserts, rigid one-piece protective shellssurrounding said inserts, said shells and inserts having lands andgrooves cooperating to yieldably hold said inserts in the shells, saidconnector being provided with circumferential space, between a saidshell and its said insert, adjacent the said opposed lace to permitradial flow of the insert under pressure, insulated conductors connectedto the remote ends of said contacts outside the inserts, and resilientprotective dielectric sleeves mounted in said shells around the endportions of said conductors and extending into compressive relation withsaid inserts.

4. An electrical connection including a pair of rigid shells having ringshaped meeting faces, means for drawing said Ashells axially togetherinto sealing relationship of said faces, resilient inserts, havingcooperating, opposed faces, seated in said shells, an internal, squareshouldered, circumierential constriction in each said shell conformingto a like external constriction in its insert, an electrical connectorhaving pin and socket parts mounted in said inserts, a said shell beingspaced from its said insert circumferentially adjacent the saidcooperating face of said insert, providing the insert with space forradial expansion under endwise compression by its cooperating insert.

5. An electrical connection including rigid protective shells, resilientinserts, having opposed, engageable faces, mounted \in said shells,cooperating electrical contacts mounted in said inserts, said shells,contacts and inserts having iii cooperating lands and grooves, means forjoining said lshells and for placing said engageable faces underpressure, and a cylindrical expansion space into which the resilientmaterial of a said insert may iiow when pressure is applied extendinginward from a said engageable face. i

6. In an electrical connector the combination of a rigid one-piecetubular shell, a resilient insert closely interfltted in said shell andhaving at least one longitudinal opening therethrough for receiving acontact, said shell and insert hav- 10 ing means for yieldably holdingthe insert in the shell, a contact mounted in said opening. saidconnector being provided adjacent its forward end with an inwardlyextending space into which the material of the resilient insert may owlaterally when subjected to endwise pressure.

7. An electrical connector element including a rigid one-piece shell, aresilient columnar dielectric insert having a major part of its lengthclosely fitted inv said shell and an end part of lesser diameter spacedfrom said shell, and a land in the shell abutting the end of thecloselyv fitted part of the insert, said land being formed in the shelland constituting a constriction through which a material length of thebody of the insert must be squeezed in dismantling the element.

8. An electrical connector including a, contact,

a resilient dielectric support encompassing and supporting said contactand having a perforated face giving admittance to said contact, a rigidshell encompassing said support and holding said support undercompression, said connector having a recess extending inward from saidface into which the material of the support may now when pressure isapplied to said face.

JAKOB R. FREI.

WILLIAM A. ULINE.

REFERENCES CITED The following references are of record in the ille o!this patent:

UNITED STATES PATENTS` Number Name Date 739,707 Park Sept. 22, 19031,686,534 Rosenzweig Oct. 9, 1928 2,265,341 Borchert Dec. 9, 19412,275,762 Horton Mar. 10, 1942 2,276,017 Brownstein Mar'. 10, 19422,286,952 Cannon et al June 16, 1942 2,291,793 Chandler Aug. 4, 19422,346,831 Drury Apr. 18, 1944 2,352,159 Brodie June 27, 1944 2,371,551Schmitt Mar. 13, 1945 2,379,942 Webber July 10, 1945 2,383,926 WhiteAug. 28, 1945

